001/*
002 * ====================================================================
003 * Licensed to the Apache Software Foundation (ASF) under one
004 * or more contributor license agreements.  See the NOTICE file
005 * distributed with this work for additional information
006 * regarding copyright ownership.  The ASF licenses this file
007 * to you under the Apache License, Version 2.0 (the
008 * "License"); you may not use this file except in compliance
009 * with the License.  You may obtain a copy of the License at
010 *
011 *   http://www.apache.org/licenses/LICENSE-2.0
012 *
013 * Unless required by applicable law or agreed to in writing,
014 * software distributed under the License is distributed on an
015 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
016 * KIND, either express or implied.  See the License for the
017 * specific language governing permissions and limitations
018 * under the License.
019 * ====================================================================
020 *
021 * This software consists of voluntary contributions made by many
022 * individuals on behalf of the Apache Software Foundation.  For more
023 * information on the Apache Software Foundation, please see
024 * <http://www.apache.org/>.
025 *
026 */
027
028package org.apache.http.impl.entity;
029
030import org.apache.http.HttpException;
031import org.apache.http.HttpMessage;
032import org.apache.http.ProtocolException;
033import org.apache.http.annotation.ThreadingBehavior;
034import org.apache.http.annotation.Contract;
035import org.apache.http.entity.ContentLengthStrategy;
036
037/**
038 * Decorator for  {@link ContentLengthStrategy} implementations that disallows the use of
039 * identity transfer encoding.
040 *
041 * @since 4.2
042 */
043@Contract(threading = ThreadingBehavior.IMMUTABLE_CONDITIONAL)
044public class DisallowIdentityContentLengthStrategy implements ContentLengthStrategy {
045
046    public static final DisallowIdentityContentLengthStrategy INSTANCE =
047        new DisallowIdentityContentLengthStrategy(new LaxContentLengthStrategy(0));
048
049    private final ContentLengthStrategy contentLengthStrategy;
050
051    public DisallowIdentityContentLengthStrategy(final ContentLengthStrategy contentLengthStrategy) {
052        super();
053        this.contentLengthStrategy = contentLengthStrategy;
054    }
055
056    @Override
057    public long determineLength(final HttpMessage message) throws HttpException {
058        final long result = this.contentLengthStrategy.determineLength(message);
059        if (result == ContentLengthStrategy.IDENTITY) {
060            throw new ProtocolException("Identity transfer encoding cannot be used");
061        }
062        return result;
063    }
064
065}